PCI/PM: Write 0 to PMCSR in pci_power_up() in all cases

Make pci_power_up() write 0 to the device's PCI_PM_CTRL register in
order to put it into D0 regardless of the power state returned by
the previous read from that register which should not matter.

Link: https://lore.kernel.org/r/5748066.MhkbZ0Pkbq@kreacher


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>